[PATCH 1/4] bpf: add IOURING program type

[Pavel Begunkov <asml.silence@gmail.com>]

Draft a new program type BPF_PROG_TYPE_IOURING, which will be used by
io_uring to execute BPF-based requests.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
 fs/io_uring.c             | 21 +++++++++++++++++++++
 include/linux/bpf_types.h |  2 ++
 include/uapi/linux/bpf.h  |  1 +
 kernel/bpf/syscall.c      |  1 +
 kernel/bpf/verifier.c     |  3 +++
 5 files changed, 28 insertions(+)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 61b65edabe5e..2c8904bee386 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -10166,6 +10166,27 @@ static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode,
 	return ret;
 }
 
+static const struct bpf_func_proto *
+io_bpf_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
+{
+	return bpf_base_func_proto(func_id);
+}
+
+static bool io_bpf_is_valid_access(int off, int size,
+				   enum bpf_access_type type,
+				   const struct bpf_prog *prog,
+				   struct bpf_insn_access_aux *info)
+{
+	return false;
+}
+
+const struct bpf_prog_ops bpf_io_uring_prog_ops = {};
+
+const struct bpf_verifier_ops bpf_io_uring_verifier_ops = {
+	.get_func_proto		= io_bpf_func_proto,
+	.is_valid_access	= io_bpf_is_valid_access,
+};
+
 SYSCALL_DEFINE4(io_uring_register, unsigned int, fd, unsigned int, opcode,
 		void __user *, arg, unsigned int, nr_args)
 {
diff --git a/include/linux/bpf_types.h b/include/linux/bpf_types.h
index 99f7fd657d87..d0b7954887bd 100644
--- a/include/linux/bpf_types.h
+++ b/include/linux/bpf_types.h
@@ -77,6 +77,8 @@ BPF_PROG_TYPE(BPF_PROG_TYPE_LSM, lsm,
 	       void *, void *)
 #endif /* CONFIG_BPF_LSM */
 #endif
+BPF_PROG_TYPE(BPF_PROG_TYPE_IOURING, bpf_io_uring,
+	      void *, void *)
 
 BPF_MAP_TYPE(BPF_MAP_TYPE_ARRAY, array_map_ops)
 BPF_MAP_TYPE(BPF_MAP_TYPE_PERCPU_ARRAY, percpu_array_map_ops)
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 77d7c1bb2923..2f1c0ab097d8 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -200,6 +200,7 @@ enum bpf_prog_type {
 	BPF_PROG_TYPE_EXT,
 	BPF_PROG_TYPE_LSM,
 	BPF_PROG_TYPE_SK_LOOKUP,
+	BPF_PROG_TYPE_IOURING,
 };
 
 enum bpf_attach_type {
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index e5999d86c76e..9b8f6b57fb1b 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -2031,6 +2031,7 @@ static bool is_net_admin_prog_type(enum bpf_prog_type prog_type)
 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
 	case BPF_PROG_TYPE_SOCK_OPS:
+	case BPF_PROG_TYPE_IOURING:
 	case BPF_PROG_TYPE_EXT: /* extends any prog */
 		return true;
 	case BPF_PROG_TYPE_CGROUP_SKB:
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index e7368c5eacb7..54e26586932b 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -7981,6 +7981,9 @@ static int check_return_code(struct bpf_verifier_env *env)
 	case BPF_PROG_TYPE_SK_LOOKUP:
 		range = tnum_range(SK_DROP, SK_PASS);
 		break;
+	case BPF_PROG_TYPE_IOURING:
+		range = tnum_const(0);
+		break;
 	case BPF_PROG_TYPE_EXT:
 		/* freplace program can return anything as its return value
 		 * depends on the to-be-replaced kernel func or bpf program.
-- 
2.24.0